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Vision is hard Humans - vision is easy - chess is hard Computers

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Presentation on theme: "Vision is hard Humans - vision is easy - chess is hard Computers"— Presentation transcript:

1 Vision is hard Humans - vision is easy - chess is hard Computers
- chess is easy

2 Origins of image variability
Illumination Scale Translation Rotation Deformation

3 Illumination invariance
Light from an object depends on illumination, as well as absorption. Even black and white depend on context. Center-surround antagonism is helpful for ignoring illumination.

4 Checker-shadow illusion
Courtesy of Professor Edward H. Adelson. Used with permission.

5 Checker-shadow illusion
Courtesy of Professor Edward H. Adelson. Used with permission.

6 Selectivity and invariance
The sensory world is in eternal flux. Yet we perceive an underlying constancy.

7 Cortical area 17 Occipital lobe Brodmann area Synonyms - area17
- primary visual cortex - V1 - striate cortes Macaque Monk y Human 1cm 1cm Area 17 Area 17 Calcarine Fissure Figure by MIT OCW. After figure in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN:

8 Simple cell receptive field
Elongated ON and OFF subregions Antagonistic organization Images removed due to copyright reasons. Please see figures a, b, and c in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, ISBN:

9 Orientation selectivity
Receptive field Visual stimulus Cell discharge Figure by MIT OCW. After figure in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN:

10 Direction selectivity
Visual stimulus Receptive field Direction of movement Direction of movement Receptive field Layer IVB cell discharge In response to left-right Stimulus movement Layer IVB cell discharge In response to left-right Stimulus movement Figure by MIT OCW. After figure in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN:

11 Complex cell receptive field
Visual stimulus Receptive field Light: ON OFF Record of Action potentials Time Figure by MIT OCW. After figure in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN:

12 Selectivity and invariance
Simple cells - selective to stimulus orientation Complex cells - invariant to stimulus location

13 Laminar organization Basic six-layer design
Striate cortex has nine layers Images removed due to copyright reasons. Please see figure in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, ISBN:

14 Columnar organization
Column: group of cells encountered in radial direction Cells in a column have similar receptive field properties

15 Cortical maps Images removed due to copyright reasons.

16 Transneuronal autoradiography
Images removed due to copyright reasons. Please see figure in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, ISBN:

17 Ocular dominance columns
Images removed due to copyright reasons. Please see figures a and b in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, ISBN:

18 Cytochrome oxidase blobs
Images removed due to copyright reasons. Please see figures a and b: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, ISBN:

19 Parallel pathways Interblob Blobs Blobs II and III II and III II and III IVB IVB IVB Striate Cortex IVC IVC IVC Magnocellular LGN Layer 2 Parvocellular LGN Layers 4 and 6 Parvocellular LGN Layers 3 and 5 Koniocellular Layers Ventral To LGN Layers 2 and 3 Koniocellular Layers Ventral To LGN layers 1 and 4 Mlagoncellular LGN Layer 1 Contralateral Retina: M-type Ganglion Cell Ipsilateral Retina: M-type Ganglion Cell Contralateral Retina: P-type Ganglion Cell Ipsilateral Retina: P-type Ganglion Cell Contralateral Retina: nonP-nonM Ganglion Cell Ipsilateral Retina: nonP-nonM Ganglion Cell Figure by MIT OCW. After figure in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN:

20 Parallel processing M channel: motion P-IB channel: Shape
Blob channel: color

21 Ocular dominance columns
Image removed due to copyright reasons. Orientation map Images removed due to copyright reasons. Please see figures B and C in Box 10.2 in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, ISBN:

22 Variation of preferred orientation
Image removed due to copyright reasons. Cortical module Images removed due to copyright reasons. Please see figures and in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, ISBN:

23 Extrastriate cortex Dorsal Stream Ventral Stream
Other Dorsal Areas Other Ventral Areas Ventral Stream Figure by MIT OCW. After figure in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, 2001. ISBN:

24 Visual areas in the human brain
Images removed due to copyright reasons. Please see figure in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, ISBN:

25 Visual motion area in humans
Images removed due to copyright reasons. Please see figure in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, ISBN:

26 Face-evoked brain activity
Images removed due to copyright reasons. Please see figure in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, ISBN:

27 Ice cube model of cortex
Images removed due to copyright reasons. Please see figure in: Bear, Mark F., Barry W. Connors, and Michael A. Paradiso. Neuroscience: Exploring the Brain. 2nd ed. Baltimore, Md.: Lippincott Williams & Wilkins, ISBN:

28 Random dot stereogram

29 Different monocular images


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